Four fire engines and around 25 firefighters were called to a house fire on Cotton Hill in Bromley.
Firefighters tackled a fire at a two-storey terraced house where an extension at the back of the property was significantly damaged by the fire.
One man left the property before the Brigade arrived and was treated for smoke inhalation by London Ambulance Service crews.
The Brigade was called at 1142 and the fire was under control by 1233. Fire crews from Bromley, Lewisham and Forest Hill fire stations attended the scene.
The fire is believed to have been accidental and caused by hot works being carried out.